[Evaluation of a Commercial Multiplex Tandem Polymerase Chain Reaction Method for the Identification of the Yeasts Isolated from Blood Cultures].

Candidemia is one of the most important health care-associated infections worldwide. Candida species have species-specific antifungal susceptibility profiles and it has been shown that the identification of the Candida species is necessary for the appropriate treatment of the patients with candidemia. Various methods are used to shorten the identification time for the determination of the causative species. Fungal ID multiplex tandem polymerase chain reaction (MT-PCR) (AusDiagnostics, Australia) is a test developed to identify yeasts and molds isolated from clinical specimens. In this study, we aimed to evaluate the Fungal ID MT-PCR test (AusDiagnostics, Australia) for the identification of the yeasts from positive blood cultures in Akdeniz University Hospital Central Laboratory. Between December 2016 and December 2017, blood culture samples from 92 consecutive patients with yeast cells detected in Gram stained smears were tested by Fungal ID MT-PCR and the reference method. After the subculture of the positive signaling blood culture bottles to Sabouraud dextroz agar (SDA), the identification of the yeasts were performed by morphological identification methods (Germ tube test, Corn Meal Tween® 80 agar media, etc.), BD Phoenix Yeast ID Panel (Becton Dickinson, Sparks, MD) and Bruker Biotyper matrix-assisted laser desorption ionization-time of mass spectrometry (MALDI-TOF MS) (Bruker Daltonics, Germany) systems. Identification with MALDI-TOF MS have been accepted as the reference method. Thirty-five of the isolates were identified as Candida albicans, 17 were Candida glabrata, 13 were Candida parapsilosis, 12 were Candida tropicalis, seven were Candida krusei , two were Candida guilliermondii, two were Candida dubliniensis, two were Candida inconspicua, one was Candida kefyr and one was Saprochaete capitata by the reference method. In our study, no blood culture sample yielded more than one yeast species. 94.6% of the strains were presumptively identified by the morphological identification methods. Discordant results were not detected between the BD Phoenix Yeast ID Panel and the reference method. Thirty-three of the isolates were identified as C.albicans, 15 were C.glabrata, 13 were C.parapsilosis, 11 were C.tropicalis, five were C.krusei , two were C.guilliermondii, one was C.dubliniensis, one was C.kefyr and 10 were Candida spp. by Fungal ID MT-PCR assay. Since C.inconspicua and S.capitata were not included in the test panel, C.inconspicua was identified as Candida spp. in two samples, while S.capitata could not be identified in one sample. Concordance between Fungal ID MT-PCR and the reference method were found to be 88% at the species level and 98.9% at the genus level. The sensitivity of the Fungal ID MT-PCR test in in the detection of C.krusei and C.glabrata was 71.4% and 88.2%, respectively. Fungal ID MT-PCR test has shown a high performance in the identification at the genus level, but the identification at the species level, which is important for the treatment management, was moderate. Fungal ID MT-PCR can be used as an adjunct test to the traditional identification methods for the early identification of the Candida species.